ALT in the polarized Drell-Yan process at RHIC and HERA energies

Abstract We present a leading order (LO) estimate for the longitudinal-transverse spin asymmetry (ALT) in the nucleon-nucleon polarized Drell-Yan process at RHIC and HERA- N → energies in comparison with ALL and ATT. ALT receives contribution from g1, the transversity distribution h1, and the twist-3 distributions gT and hL. For the twist-3 contribution we use the bag model prediction evolved to a high energy scale by the large-Nc evolution equation. We found that ALT (normalized by the asymmetry in the parton level) is much smaller than the corresponding ATT. Twist-3 contribution given by the bag model also turned out to be negligible.